VALCANOES Essay Example For Students

VALCANOES Essay Volcano This paper will define and discuss the volcano to include: types of volcanoes, formation of a volcano, and elements of a volcano; such as, lava, rock fragments, and gas. This paper also tells a little bit about volcanic activity in different parts of the world. What is a volcano? A volcano is a vent in the earth from which molten rock and gas erupt. The molten rock that erupts from the volcano forms a hill or mountain around the vent. The lava may flow out as a viscous liquid or it may explode from the vent as solid or liquid particles. Kinds of Volcanic Materials Three basic materials that may erupt from a volcano are; 1. lava, 2. rock fragments, and 3. gas. Lava Lava is the name for magma that has been released onto the Earths surface. When lava comes to the Earths surface, it is red hot and may have temperatures of more than 2012 degrees Fahrenheit. We will write a custom essay on VALCANOES specifically for you for only $16.38 $13.9/page Order now Fluid lava flows swiftly down a volcanos slopes. Sticky lava flows more slowly. As the lava cools, it may harden into many different formations. Highly fluid lava hardens into smooth, folded sheets of rock called pahoehoe. Stickier lava cools into rough, jagged sheets of rock called aa. Pahoehoe and aa cover large areas of Hawaii, where the terms originated. The stickiest lava forms flows of boulders and rubble called block flows. It may also form mounds of lava called domes. Other lava formations are spatter cones and lava tubes. Spatter cones are steep hills that can get up to 100 feet high. They build up from the spatter of geyser-like eruptions of thick lava. Lava tubes are tunnels formed from fluid lava. As the lava flows, its exterior covering cools and hardens. But the lava below continues to flow. After the flowing lava drains away, it leaves a tunnel. Rock Fragments Rock fragment are usually called tephra and are formed from sticky magma. This magma is so sticky that its gas can not easily escape when the magma approaches the surface or central vent. Finally, the trapped gas builds up so much pressure that it blasts the magma into fragments. Tephra consists of volcanic dust, volcanic ash, and volcanic bombs, (from smallest to largest size particle). Volcanic dust consists of particles less than one one-hundredth inch in diameter. Volcanic dust can be carried for great distances. In 1883, the eruption of Krakatau in Indonesia shot dust 17 miles into the air. The dust was carried around the Earth several times and produced brilliant red sunsets in many parts of the world. Some scientists assume large quantities of volcanic dust can affect the climate by reducing the amount of sunlight that reaches the Earth. Volcanic ash is made up of fragments less than one fifth inch in diameter. Nearly all volcanic ash falls to the surface and becomes welded together as rock called volcanic tuff. Sometimes, volcanic ash combines with water in a stream and forms a boiling mudflow. Mudflows may speeds up to 60 miles per hour and can be remarkably shattering. Volcanic bombs are large fragments. Most of them range from the size of a baseball to the size of a basketball. The largest bombs can measure up to more than four feet across and weigh up to 100 short tons. Small volcanic bombs are generally called cinders. Gas Gas pours out of volcanoes in large quantities during almost all eruptions. The gas is made up particularly of steam, but may also include carbon dioxide, nitrogen, sulfur dioxide, and other gases. Most of the steam comes from a volcanos magma, but some steam may also be produced when rising magma heats water in the ground. Volcanic gas carries a large sum of volcanic dust. .u9ca939d45e78e60286d2a8d01bd126fc , .u9ca939d45e78e60286d2a8d01bd126fc .postImageUrl , .u9ca939d45e78e60286d2a8d01bd126fc .centered-text-area { min-height: 80px; position: relative; } .u9ca939d45e78e60286d2a8d01bd126fc , .u9ca939d45e78e60286d2a8d01bd126fc:hover , .u9ca939d45e78e60286d2a8d01bd126fc:visited , .u9ca939d45e78e60286d2a8d01bd126fc:active { border:0!important; } .u9ca939d45e78e60286d2a8d01bd126fc .clearfix:after { content: ""; display: table; clear: both; } .u9ca939d45e78e60286d2a8d01bd126fc { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .u9ca939d45e78e60286d2a8d01bd126fc:active , .u9ca939d45e78e60286d2a8d01bd126fc:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .u9ca939d45e78e60286d2a8d01bd126fc .centered-text-area { width: 100%; position: relative ; } .u9ca939d45e78e60286d2a8d01bd126fc .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .u9ca939d45e78e60286d2a8d01bd126fc .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .u9ca939d45e78e60286d2a8d01bd126fc .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .u9ca939d45e78e60286d2a8d01bd126fc:hover .ctaButton { background-color: #34495E!important; } .u9ca939d45e78e60286d2a8d01bd126fc .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .u9ca939d45e78e60286d2a8d01bd126fc .u9ca939d45e78e60286d2a8d01bd126fc-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .u9ca939d45e78e60286d2a8d01bd126fc:after { content: ""; display: block; clear: both; } READ: Professional Wrestling Essay This alliance of gas and dust looks like black smoke Types of Volcanoes The magmas that are the most liquefied erupt quietly and flow from the vent to form sloping shield volcanoes, a name that is conceived because they look like the shields of ancient German warriors. The lava that flows from shield volcanoes is usually only one to ten meters thick, but the lava may extend for great distances away from the vent. The volcanoes of Hawaii and Iceland are typical shield volcanoes. Magma with high gas contents and high viscosities are usually more explosive than the lava that flows from shield volcanoes. This gas-rich lava in many occurrences is blown very high into the air during an eruption. The magma falls as volcanic bombs, which accumulate around the vent and form steep-sided but relatively small cinder cones. volcanic bombs range in size from fine-grained ash to house-size blocks. Cinder cones most commonly consist of volcanic fragments any where from ash to small- pebble size which is less than three centimeters in diameter. Most of the tallest volcanoes are composite volcanoes, which are also called stratovolcanoes. These form a cycle of quiet eruptions of fluid lava followed by explosive eruptions of viscous lava. The fluid lava creates an erosion resistant shell over the explosive debris, which forms, strong, steep-sided volcanic cones. In the past, giant eruptions of extremely fluent basaltic lava from extensive systems of fissures in the Earth have occurred. These series of eruptions formed large plateaus of basaltic lava. In India, the Deccan basalts cover 260,000 square kilometers, and in Oregon and Washington the Columbia Plateau basalts cover approximately 130,000 square kilometers. No eruptions of this extent have ever been observed during historical times. Even more voluminous accumulations of basaltic lava, nevertheless, are currently being formed at the mid-ocean ridges. How a volcano is formed The Beginning A volcano begins as lava inside the Earth. This lava is created from extreme temperatures in the Earths interior. Most magma forms 50 to 100 miles beneath the Earths surface. Some magma develops at depths of 15 to 30 miles below the Earths surface. The magma, which is now filled with gas from combining with the other rock inside the Earth, progressively rises toward the Earths surface because it is less dense than the solid rock around it. As the magma rises, it melts gaps in the surrounding rock and forms a large room as close as two miles to the surface. The magma room that is formed is the reservoir from which volcanic materials erupt. The Eruption The gas-filled lava in the reservoir is now under great pressure from the weight of the solid rock around it. the pressure causes the gas to blast or melt a channel in a fractured or weakened part of the rock. The magma now moves through the channel to the surface. When the magma gets near the surface, the gas in the magma is released. The gas and magma blast out an opening called the central vent. Most of the lava and other volcanic materials then erupt through this vent. The materials gradually pile up around the vent, and form a volcanic mountain, or a volcano. After the eruption stops, a bowllike crater usually forms at the top of the volcano. The vent lies at the bottom of the crater. Once a volcano has formed, not all the lava from later eruptions reaches the surface through the central vent. As the magma rises, some of it may break through the channel wall and branch out into smaller channels in the rock. The magma in these channels may escape through a vent made in the side of the volcano, or it may rest below the surface. Volcanoes are very wondrous and amazing. .u96da93c2aaa94e91001dbb46c3d030a7 , .u96da93c2aaa94e91001dbb46c3d030a7 .postImageUrl , .u96da93c2aaa94e91001dbb46c3d030a7 .centered-text-area { min-height: 80px; position: relative; } .u96da93c2aaa94e91001dbb46c3d030a7 , .u96da93c2aaa94e91001dbb46c3d030a7:hover , .u96da93c2aaa94e91001dbb46c3d030a7:visited , .u96da93c2aaa94e91001dbb46c3d030a7:active { border:0!important; } .u96da93c2aaa94e91001dbb46c3d030a7 .clearfix:after { content: ""; display: table; clear: both; } .u96da93c2aaa94e91001dbb46c3d030a7 { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .u96da93c2aaa94e91001dbb46c3d030a7:active , .u96da93c2aaa94e91001dbb46c3d030a7:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .u96da93c2aaa94e91001dbb46c3d030a7 .centered-text-area { width: 100%; position: relative ; } .u96da93c2aaa94e91001dbb46c3d030a7 .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .u96da93c2aaa94e91001dbb46c3d030a7 .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .u96da93c2aaa94e91001dbb46c3d030a7 .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .u96da93c2aaa94e91001dbb46c3d030a7:hover .ctaButton { background-color: #34495E!important; } .u96da93c2aaa94e91001dbb46c3d030a7 .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .u96da93c2aaa94e91001dbb46c3d030a7 .u96da93c2aaa94e91001dbb46c3d030a7-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .u96da93c2aaa94e91001dbb46c3d030a7:after { content: ""; display: block; clear: both; } READ: The Importance of Voting Essay They are one of the most destructive and one of the most beautiful things on this Earth. They contain gas, lava, and tunnels that go many miles into the Earth. They can form new islands or gigantic mountains. The materials that volcanoes erupt can help scientists understand about the inner Earth. Bibliography Bullard, Fred M. Volcanoes of the Earth. Austin: University of Texas Press, 1962. Decker, Robert and Barbara. Volcanoes. San Francisco: W.H. Freeman and company, 1981. Decker, Robert and Barbara. Volcanoes. New York: W.H. Freeman and company, 1981. Macdonald, Gordon A. Volcanoes. New Jersey: Prentice-Hall, inc. , 1972. Volcano, The World Book Encyclopedia, 1993, Volume 20, pages 438-440.

Hawaiian Sugar Plantation essays

Hawaiian Sugar Plantation essays In the 1890s, plantation owners devised a plan to use and maintain their cheap labor. Early laborers consisted of mainly Japanese and Chinese origin. Fear of strikes from Japanese laborers occurring and running their plan to continue the cheap labor to the ground caused managers to recruit other workers from other countries. When the contract labor system was terminated, the Hawaiian Sugar Planters Association organized ways to keep wages low. One way they constituted their plan was to form wage-fixing agreement between the plantations. Even with laws and restrictions going against immigration of more people from other countries, the association just resorted to other sources of legal labor.. They find workers from other countries like Philippines and Korea. When strikes did break out, it was resolved, such as the 1920 strike in Oahu. Numerous strategies were improvised and were maintained for a period of time to keep wages low, but the efficiency wore down as numerous attempts w ere made by laborers to counter strike with their ways of retaliation. Many sugar plantation laborers were mainly from China and Japan (Takaki, 25). Chinese and Japanese workers were placed on the plantation together to phase off the possibility of disputes or strikes with plantation owners. The first tactic they used was combining Chinese laborers with Japanese laborers, regulating a certain ratio of 2/3rd between the Chinese and Japanese (Takaki, 26). Their hypothesis was that the feud or disputes between the two races would occupy them enough to prevent them from causing an opposition upon the owners. Their plan to use Chinese to dilute the Japanese population on the field was shot down after the annex of Hawaii to The United States Of America. Chinese immigrants were not allowed because immigration laws. In place of the Chinese, Koreans were brought in with the notion that they had enmity toward Japanese. Korean workers started to...

Racial Profiling on Drug Warfare Essay Example | Topics and Well Written Essays - 2000 words

Racial Profiling on Drug Warfare - Essay Example However, one can recognize the modest changes in white racist domination in the United States without downplaying the strong relationship between being black and being a target of serious racial discrimination. In one way or another, all black Americans and Caucasians continue to suffer discrimination because white domination of black Americans and other people of color remains a major organizing principle for group life in the United States. According to statistical results "Although African Americans comprise only 12.2 percent of the population and 13 percent of drug users, they make up 38 percent of those arrested for drug offenses and 59 percent of those convicted of drug offenses causing critics to call the war on drugs the "New Jim Crow" (Race and the Drug War n.d.). The racial hierarchy is supported by a range of dominant-group prejudices and stereotypes, yet it is perpetuated most centrally by the discrimination carried out by many whites on a recurring basis. Age-old pattern s of racial inequality-of unjust enrichment and unjust impoverishment-are reproduced by the daily routines of antiblack discrimination. For instance, "During the height of the war on drugs, from 1986 to 1991, the number of white drug offenders in state prisons increased by 110 percent. The number of black drug offenders grew by 465 percent" (Shaw 2000). Police pays a special attention to African-Americans and Caucasians because of ethical differences and stereotypes. It should be no surprise then, that African Americans are often depicted as criminals in mass media. Crime in America is often portrayed in blackface, seemingly suggesting not only that African Americans and Caucasians are likely to be involved in crime, but that they are responsible for most of the crime in America today. "Racial profiling is the law enforcement practice of substituting skin color for evidence as grounds for suspicion" (Race and the Drug War n.d.). Contemporary patterns of discrimination are grounded in the benefits that whites have historically secured. All forms of racial discrimination transmit the legacy of the past, that of slavery and legal segregation. Today discriminatory practices reproduce and reinforce the unjust impoverishment and enrichment of the past. Discrimination also reflects and perpetuates the age-old racist ideology, with its asso ciated array of anti-black images and attitudes. When blacks and Caucasians encounter whites in a broad array of contemporary settings, they often meet negative beliefs about their abilities, values, and orientations. Racial barriers persist today because a substantial majority of whites harbor anti-black sentiments, images, and beliefs and because a large minority are very negative in their perspectives. When most whites interact with black Americans at work, in restaurants, on the street, at school, or in the media they tend to think about the latter, either consciously or unconsciously, in terms of racist stereotypes inherited from the past and constantly reiterated and reinforced in the present (Daum 65). Police may actively persecute blacks, or they may engage in an array of avoidance behaviors.